The invention relates generally to the detection of fault and failure conditions in vehicle tires and particularly to the detection of overheating, inadequate inflation, and excessive deflation in pneumatic tires for both on and off road vehicles.
Excessive heating, inadequate inflation, and rapid or excessive deflation of pneumatic tires have been long recognized as serious problems with pneumatic tires because the sudden failure of a tire on a moving vehicle, such as a truck or passenger car, gives rise to hazardous circumstances which frequently cause serious accidents and often fatalities. Accordingly, there is a substantial need in the art for a device which will indicate the pending failure of a tire due to either of these causes. The need for such a device has long been recognized in the art as is evidenced by U.S. Pat. No. 4,117,452. This patent discloses a device which is responsive to the deflation of a tire and explains in rather substantial detail the need for such a device. However, the device described in this patent is typical of prior art devices presently available. Typically, the prior art attempts to utilize apparatus and techniques which require special wiring and which also need special transmitters, receivers, and various types of antenna. Furthermore, none of the presently available prior art devices are responsive to all tire failure conditions of excessive temperature, inadequate inflation, or excessive deflation of the pneumatic tire.
It should be understood by those skilled in the art that although the invention is described as being primarily applicable in the art of pneumatic tires, the invention has merit also in any environment in which an inflatable member serves as a load bearing member, the configuration of which is dependent upon either proper inflation or acceptable temperatures.